In a first aspect of the invention, many patients desire mobility and independence. Conventional patient controlled powered wheelchairs are front entry in that the supporting structure is under and behind the seated user, and even though they provide great mobility, the conventional wheelchair is hampered by front entry when lifting and transfer capabilities are added. Conversely, wheeled patient transfer-lifts are usually rear entry in that the patient faces and is suspended from the lifting structure. Also, transfer-lifts are nearly exclusively operated by a caregiver even though the patient being lifted and transported may have significant capabilities. Rear entry transfer-lifts offer an advantage in transfer operations by the natural orientation of the patient that compliments transfer to other equipment or furnishings. It is easier to place a patient into a front entry conventional wheelchair or place a patient on a bed or toilet from a rear entry transfer-lift device. Wheeled transfer-lifts have rear wheel support arms that can be widened to improve stability when the lift is elevated.
There are numerous patient lift devices that have adequate lifting capability for certain situations; however those with lifting range sufficient to lift a patient from lying on the floor to standing height are not both compact and mobile. There are ceiling mounted lifts with great lifting range but these are confined to a ceiling track or large frame structure. There are boom arm lifts with fairly high lifting range but to increase lifting range these lifts have long boom arms and long support structures to achieve the greater lift range. There are jackscrew driven and hydraulic driven vertically guided lifts that have high lift ranges but these lifts have very tall guide support structures that increase their height and reduce their mobility.
Wheeled lifts are often used to aide in transferring to a conventional wheelchair and therefore have support structures that straddle the wheelchair during this transfer operation. Moving to and from the wheelchair, such wheeled lifts must often pass through common width doorways so the width of the support structure must have a means to be reduced. Therefore, most wheeled lifts have provisions to move some portion of the support structure from wide to narrow width as needed. Many wheeled lifts have outwardly pivoting wheel support arms that can be swung outward to widen the structure for transfers to and from a wheelchair. The required wide angle of the wheel support arms results in a width between the ends of the pair of extended arms that is much wider than the wheelchair. A few lift types have sidewardly sliding sections that provides a wider opening for straddling a wheelchair.
Commonly, wheeled lifts have a single central column at one end from which the boom arm extends or the lifting section telescopes. This structure simplifies the lift mechanism but the structure resulting from this central location interferes with the patient's knees and also makes it difficult to locate the lifting point of the lift close enough to a patient that is lying on the floor.
U.S. Pat. No. 6,430,761 describes a Compact Portable Patient Lift that is intended to be portable but it has inadequate lifting range to lift a patient from lying on the floor to standing, it has an interfering central lifting support column and does not provide the capability for self-lifting or patient driving. U.S. Pat. No. 4,719,655 describes a patient lift with two telescoping vertical guide columns but also has an interfering central lift mechanism and no means to adjust the width of the wheel support arms. U.S. Pat. No. 6,161,232 describes an Invalid Lifting Device having two vertical lifting columns, each having front and rear wheels wherein the columns can be adjusted to the desired width from the other. However, this device has very tall columns to achieve the high lift range and has no provision for patient operation of the lift. U.S. Pat. No. 5,466,111 describes a method wherein the seat lift of a wheelchair is used to raise a wheelchair and patient occupant into a vehicle by attaching the upper portion of the wheelchair to the vehicle door and then swinging the door shut to move the wheelchair and occupant into the vehicle. However, this method requires a vertically hinged door to carry the raised wheelchair and most vehicle floors are too high for the illustrated seat lift to achieve an adequate height to clear the vehicle floor to allow entry and this method will not work when the vehicle door has a horizontal hinge axis like a van rear door.
U.S. Pat. No. 6,092,247 for a Powered Patient Lift Vehicle, describes an earlier attempt by the present inventor to provide a patient operated lift that could also be driven as a wheelchair. However, this device achieves some of the capabilities of the present invention, but it has the long boom arm affect, the outwardly swinging wheel arm supports, and is too large for easy portability in a vehicle. It also does not assist in raising the device itself to higher levels. U.S. Pat. No. 5,255,934 is another earlier attempt by the present inventor to provide a power driven wheelchair with a lifting capability. However, this is a front entry wheelchair with the lift motor, battery and cross shaft below the patient which eliminates the ability to move over a patient lying on the floor. There is no provision to move the rear wheel support arms outward to improve stability when elevated. Also, this device has only a single jack screw in each lift column and the lift column height increases directly proportional to the lift stroke which makes the higher lift version too tall when retracted. There is no provision or lift range for using the lift mechanism for self lifting the entire unit from one level to a higher level.
There is a need for a patient-operated rear entry lifting, rotation, transfer and transporting device that can also serve as a wheelchair that is compact enough to fit inside a vehicle and easily transported for use at another location.
The ideal wheelchair lift-transfer device of the invention provides capabilities for a patient to independently control the wheelchair and lift functions to elevate and move about safely so that he or she can communicate eye to eye with others and retrieve items that are normally too high to reach. Such independence would be demonstrated by the patient when they grasp a handheld wireless remote control and summon their wheelchair lift-transfer device from across the room, to their bedside, then independently transfer into the device and then drive it about in their home, raising and lowering their body as needed. Later they can drive to their bed, lower their self onto the bed, release from the lift and then with the handheld wireless remote control, drive the wheelchair lift-transfer device clear of their sleeping area. For certain performance requirements, the patient may need to transfer to their conventional power drive wheelchair. The independent patient can drive the wheelchair lift-transfer device over to their conventional wheelchair, adjust the rear wheel support arm width as needed, reverse the direction of the wheelchair lift-transfer device and lower themselves onto their conventional wheelchair and then complete the transfer by driving the wheelchair lift-transfer device away from the user, now in the conventional wheelchair, into a parking position by use of the handheld wireless remote control.
When a caregiver is present and can assist in the operation, this ideal wheelchair lift-transfer device of the invention will provide even more capabilities such as by raising the patient off of the floor and placing them in a seated position on a chair or bed or, standing them up on the floor. In this case, the wheelchair lift-transfer device of the invention will also be configured to utilize the integral lifting capability to not only lift the patient but also to lift a conventional wheelchair or other equipment into a vehicle and subsequently lift the wheelchair lift-transfer device its self into a vehicle or lift it from a lower level floor, upward, for use on a higher level floor or platform. The inventive wheelchair lift-transfer device includes integral sensors and control logic that will minimize unsafe use.
In a second aspect of the invention, frequently patients must be transferred from their conventional wheelchair, transported through narrow isle ways and then transferred to a stationary seat, such as an aircraft passenger seat. When a patient's conventional wheelchair will be transported as aircraft baggage a patient may be transferred to a conventional push chair at the gate and then transferred again to an “Isle Chair” just inside the aircraft cabin. An isle chair is narrow and a supported patient is moved down the aisle to their seat location where they must be lifted from the aisle chair into a passenger seat. This procedure can cause injury to both a patient and attendants.
U.S. Pat. Nos. 4,639,012, 4,639,012 and 6,929,275 are examples of Aisle Chairs. They are basically narrow chairs that fit the narrow aircraft aisle ways with no features provided for elevating the patient to aide in transfer from a conventional wheelchair or to an aircraft seat. U.S. Patent Application Publication US 2010/0251481 discloses a lifting device apparently intended to accomplish many of the same objectives of this invention; however the device, having an overhead lifting frame, is too large and too tall for practical use and storage within the aircraft. U.S. Patent Application Publication US 2009/0144895 discloses a lifting device having overhead patient lifting and rotation features that is also too large and too tall for practical use within an aircraft.
There is a need for an improved wheeled patient lift-transfer device that will lift a patient from a conventional wheelchair, transport him or her through narrow passage ways, rotate him or her to face in a desired direction and lower him or her on to a stationary seat that may be confined on all sides by other seats or structures. The lift-transfer device can be propelled by the attendants or could be provided with electric motor drives for both transport and lifting energy.
Therefore, the objects of the present invention are to provide:
1. A compact patient lift-transfer device with increased lifting range, including lifting a patient from lying on the floor to standing position yet have a retracted column height that will pass under a normal height table top.
2. A compact wheelchair lift-transfer device that improves transfer to and from conventional wheelchairs by providing a pair of independently adjustable rear wheel support arms that remain substantially parallel when they are adjusted, including a range of adjustment that allows a narrow position for passage of the pair of support arms under and between the wheels of a conventional wheelchair and a wide position that allows space for a chair to sit between the wheel support arms and/or provide improved stability for driving the wheelchair lift-transfer device with the lift elevated.
3. A compact rear entry wheelchair lift-transfer device that improves transfer to and from a bed including a semi-rigid seat plate that can be easily placed under a patient who is on a bed and be quickly attached to the lift.
4. A compact patient controlled power drive wheelchair lift-transfer device that can serve as a rear entry lift transfer that can carry the patient around the house, place them on a toilet, sit them close up to a table or lift them up to reach high objects such as in a kitchen cupboard.
5. A compact patient wheelchair lift-transfer device that provides patient independence by providing a battery powered wheelchair lift-transfer device that can be remotely controlled by the patient to bring the device to the patient who is in a bed or in a conventional wheelchair and then allow the patient to control the lift to cause it to lift the patient from the bed or wheelchair and then drive the lift transfer device to another location with patient carried along and under control of the patient.
6. A compact patient wheelchair lift-transfer device that is easily transportable and self lifting for transfer into a vehicle that can be used to lift and transfer a patient from a conventional wheelchair into a vehicle seat, then be used to lift the conventional wheelchair into the vehicle and finally provide a self lifting means to lift the wheelchair lift-transfer device into the vehicle to be taken along to lift all the above out of the vehicle again, later.
7. An optional compact patient wheelchair lift-transfer device having a U-shaped patient lifting frame that includes rotation, lifting and driving means.
8. A compact lift-transfer device that improves transfer to and from conventional wheelchairs by providing a U-shaped rotatable lift frame that positions and supports the patient substantially within the U-shaped frame thereby keeping the patient's center of gravity within the U-shape (as viewed from above), the patients backside facing outward through the open side of the U-shape and the height of the lift structure reduced.
9. A U-shaped lifting frame that forms a rotation track that is supported on a series of rollers or bearing surfaces that allows the U-shaped frame to be rotated as the track moves through the series of supporting rollers, thereby rotating the lifting frame and patient about a vertical axis.
10. An optional compact lift-transfer device having a wheeled base with at least 3 supporting wheel locations whereby the frame of the base can be adjusted so at least one wheel is moved to a position closer to the other wheels so that the base width becomes substantially narrowed to allow the lift-transfer device to pass through a narrow passage way.
11. An optional compact patient lift-transfer device wherein the patient U-shaped lifting frame may be moved to position the patient over the wheeled base into the most favorable position for stability of the patient and transfer device when considering the width of the wheeled base.
12. An optional compact patent lift-transfer device having at least one offset substantially vertical lifting column, the upper end of which a U-Shaped lifting frame is cantileveringly attached so that the U-shape of the lifting frame is oriented substantially horizontal and located generally above the wheeled base.
13. An optional compact patient lift-transfer device wherein the wheeled base has at least one wheel support arm that is pivotally mounted to allow base width adjustment.
14. An optional compact lift-transfer device wherein the patient can be rotated 90 degrees about a vertical axis when the base wheel locations have been adjusted to provide increased stability.
15. An optional compact lift-transfer device that can be assembled to serve as either a Right Hand or Left Hand device, that being a Right Hand Device when the patient is transferred into a seat on the right side of an isle way as the patient faces forward or Left hand device when the patient is placed on the left side of the isle way when facing forward.
Other objects and purposes of the invention, and variations thereof, will be apparent upon reading the following specification and inspecting the accompanying drawings.
Certain terminology will be used in the following description for the convenience in reference only, and will not be limited. For example, the word “front” will refer to the side of the wheelchair lift-transfer device that faces the pair of double telescoping lifting columns that is opposite the side from which the cantilevered horizontal seat support arms extend; this being the side facing the lower right of FIG. 1.
With respect to the wheelchair lift-transfer device, the abbreviation “RH” which means “right hand” and “LH” which means “left hand” as related to the patients right hand or left hand as he or she is supported in the wheelchair lift-transfer device while seated and facing in the same direction as the wheelchair lift-transfer device “front” faces. The words “inwardly” and “outwardly” will refer to directions toward and away from, respectively the geometric center of the wheelchair lift-transfer device and designated parts thereof. Said terminology will include the words specifically mentioned, derivatives thereof, and words of similar import.